Metal-working machine



Sept. 15, 1925. 1 1,554,101

A. KREBS ET AL METAL WORKING MACHINE Filed Sept. 16. 1924 4 Sheets-Sheet1 I ezeralars fieh limh m mfimnw 6, a m u wm m :J 5 4 a L ww 4 U 7 R A mM J 0 4 1L J M. A u M. .L w F 9 Sept. 15, 1925,.

Sept 15, 1925-. 1,554,101

A. KR EBS ET AL METAL WORKING MACHINE Filed Sept. 16 1924 4 Sheets-Sheet4 jade 72 207 6 I602 767-1266,

Patented Sept. 15, 19 25.

- UNITED STATES PA-TENT OFFICE.

ADOLF KREBS, F BOSTON, AND REXFORD B. G UPTILL, 0]! CAMBRIDGE, MASSACHU-SEE-TS; SAID GUPTILL ASSIGNOR TO SAID KBEBS.

METAL-WORKIN G MACHINE.

Application filed September 16, 1824. Serial No. 787,986. I

To all whom it may concern:

Be it known that we, Anonr Knnns and REXFORD B. GUPTILL, citizens ofGermany and the UnitedStates of America, respectively, and residents ofBoston and Cambridge, in the counties of Suffolk and Middlesex,respectively, and State of Massachusetts, have invented new and usefulImprovements in Metal-Working Machines, of

which the followin is a specification.

ThlS invention re ates to machlnes for automatically moving andcontrolling the movements of an operative instrumentality being cut, sothat the finished s ape in many instances fails to conform as closel asdesired to the template or pattern. uch inaccuracy in operation has beenoccasioned in most cases'from one of two general causes: first, theemployment of a template following roll or other guide element of solarge a size that it is unable accurately to follow the contour of thetemplate, especially if such contour includes sharp turns, curves, orre-entrant angles; and second from the practice of transmitting movementof the template following element to the cutting .instrumentality bythe'use of links or lever arms, such arrangements even though carefullyconstructed, exhibiting a certaln degree of lost motion.

Objects of the invention are to provide an improved apparatus foraccurately and reliably cutting, welding or carrying out otheroperations along a path corresponding to a given pattern or template andto arrange the apparatus so that it is adapted to use an extremelysimple form of template readily constructable from cheap and easilyobtainable material such as cardboard, fiber, wood, or other easilyworkable material, the arrangement being such that the template is notrequired to support any additlonal weight; and to prov1 e means fordriving the template followers at substantially a constant average speedso that the cutting element is moved reliably and accurately to accordto the shape of the template.

Three concrete embodiments of the invention are illustrated on theaccompanying drawings, in which: i Fig. 1 is a perspective view of atorch cutnggnachme 1g. 2 1s a vertical section showing the mechanism foroperating the template follower;

Fig. 3 is a bottom view of the follower;

Fig. is a side elevation of the template follower operating mechanism;

Fig. 5 is an elevation artly in section of a modified form adapte fortracing drawmgs;

Fig. 6 is an elevation showing the driving connection for the mechanismshown in Fig. 5;

Fig. 7 is a front elevation of further modification; and

Fig. 8 is a section on the line 8-8 of Fig. 7.

In the particular form of the invention illustrated in Figs. 1 to 4, ablow-torch is mounted for universal movement in a horizontal plane.Template followers are mounted in a vertical position on the support forthe blow-torch and are connected to e driven by a motor, the followers.fitting over and rotating along the edge of the template. Mechanismpermits the followers to move around curves and irregularities in thecontour of the template without change of speed, so that the averagespeed ofthe followers is not varied, but kept constant at all timesregardless of the number of sharp turns, curves or re-entrant angles inthe template.

Referring to Fi 1 to 4, the blow-torch or other instrumenta ity 1arranged to project a cutting blast vertically downward is supportedfrom a carriage 2 mounted on wheels 3, supported in tracks 4 forrestricting themovement (if the carriage 2 to linear movement withrespect to a carriage 5 on which the tracks are mounted. Carriage 5 isprovided with wheels 6. supported on horizontal tracks 7 which restrictthe carriage to linear movement transverse to that of the carriage 2.

Motor 8 is supported on anupright bracket 9 secured to a platform orturntable 10 18' are journaled in brackets 19 and arms 20 a secured tothe bracket 9 which bracket support the outer ends of the shafts.Meshing with the pinions 17" and 18 are pinions 21 and 22 respectivelyfast to vertical shafts 21 and 22, the upper ends of which are journaledin the bracket arms 20 and the lower ends are journaled in the platform10. Fast to the shafts 21 and 22' are gears 23 and 24 respectivelymeshing with gears 25 and 26 respectively secured to the templatefollower shafts 25 and 26. Supporting the shafts 25 and 26 is a slide 27which is axially movable in an extension 28 integral with the platform10, the lower ends of the shafts being mounted in antifriction bearingsin a head 29 fitting within the slide 27.' Relative rotative' movementbetween the slide 27 and extension 28 is prevented by a screw 28 in theextension 28 which extends into an elonate slot 27* in the slides 27.

Fast to the ends of the template follower shaft 25 and 26 are templatefollower members 30 and 31 respectively, frusto-conical in form andhavin axial ridges or otherwise provided with frlctiona-l surfaces forengagement with vertical edges of thestrip 32 constituting the templateor pattern. The template 32 of relatively soft metal, cardboard, fiber,wood or other easily worked material rests upon the table 33, or ifdesired may be clamped in position although this is not required owingto the smoothness of operation of the mechanism.

The template follower members 30 and 31 are held in contact with thetemplate by a weight 34 bearing against the head 29 and adapted to slideon the extension 28 to permit the members to be moved axially away fromthe template.

In operating the machine,gthe template follower members 30 and 31 aremoved into engagement with the opposite edges of the template strip 32,the weight 34 holding the members in position. Motor 8, acting throughthe series of gears described causes rotation of the follower members 30and 31 in the same direction. The template followers are thusautomatically moved by rolling along the edges of the template, therebypropelling the carriage 2 and torch 1 synchronously in accordance withthe contour of the template, the followers being adapted to turntogether owing to the rotatable connection betweenthe platform 10 andplate 11. In moving in and out of angles and or diminish with respect tothe other. In

this manner the torch is moved continuously at the same speedirrespective of the number and magnitude of the irregularities on thesurface of the template. The material being worked upon isaccordingly'cut along the path 36 indicated by the full line, the dottedline in continuation of line 36 representing the path to be cut by thetorch upon further movement of the followers along the template. Thusthe block of metal or other material 35 is cut accurately to conform tothe pattern of the template 17 without adjustment or manipulation by theoperator other than positioning the follower members and energizing themotor.

In orderto stop the propulsion of the template followers 30 and 31 andthe torch 1, it is only necessary to displace the shafts 25 and 26slightly from the edge of the template by raising the slide 27 thusinstantly stopping further travel of carriage 2 and thetorch by directlyapplied manual control. To start again it -is merely necessary toreestablish contact between the follower members and template.

In the embodiment of the invention illustrated in Figs. 5 and 6, motor 8is supported directly on the platform 10 and is provided with the rotorworm 12 meshing with the gear 13 carried by a shaft 37 rotatable in abearing 38. Extending into and rotatable with the shaft 37 is a shaft 39which is splined thereto for longitudinal adjustment. The end of theshaft 39 extends into a housing 41 i and has a annular groove 42receiving the end of a screw 43 to permit relative rotative movementbetween the shaft and housing. Fixed to the end of the shaft '39 is apinion 44 meshing with gear 45 fast to shaft 46 which is provided withaj'worm 47. The

worm 47 meshes with a gear 48 fixed to the guided manually over thelines on the. print,

the blow-torch being accordingly moved as above described. It is merelynecessary for the operator to grasp the casing 41 or other suitable partto guide the pointer, the wheels the turns or angles described by thepointer.

Under some conditions it is desirable to support the tem late directlyon the material to be worke upon, thus to eliminate the tracks for thecarriage, and, as in the first form described the driven templatefollowers propel the carriage along, the carriage functioning tomaintain the followers in planes at substantially right angles to thehorizontal plane of the template. For this purpose, the drivingmechanism is similarly mounted on a platform 10' having an integraltubular extension 28 within which fits sleeve 27 supporting the drivenfollower shafts 25 and 26 to which are fixed template followers 31' and32 arranged for rolling contact with the opposite edges of the template32, the above mechanism being substantially the same as above described.Also mounted on the platform 10' is a bracket 53 supporting a horizontalrod 54 to which is attached a vertical rod 55 for supporting inavertical position the blow-torch 1 clamped thereto.

Formed in the extension 28' are annular grooves 56 around which fitbrackets 57 forming an integral part of the section A of the machinecarriage, the brackets being held in place by semi-cylindrical straps 58bolted thereto. Extending rearwardly of the carriage section A andpivoted thereto to swing in substantially a horizontal plane is thecarriage section B to which are journaled a pair of wheels 59, which maybe provided with rubber tires to prevent slipping. It will be observedthat the motor is mounted rearwardly on the platform 10 so that thecenter of gravity is in rear of the vertical axis of the machine. Inthis manner the machine tends to tilt to the rear. in .order that thewheels 57 may'aid in supporting the weight and liability of the machinetilting forwardly is prevented.

It will be apparent that in this form the template 32' is placeddirectly upon the material 35 bein worked upon and the followers 31 and32 propel the carriage in accordance with the contour ofthe template,the blow-torch being synchronously moved along the material. Thismachine otherwise operates in the same manner as that shown in Figs. 1to 4. a

It will be evident that an outstanding characteristic of the inventionconsists in the provision of a differential for insuring the even andregular movementof the drivers so that at aIltimes the average speed ofthe drivers is constant. This is advantageous because there. is noliability of the blowtorch stopping at intervals which would tendseriously to impair eflicient results. Another ing tendency.

particularly advantageous feature of the inventlon consists in mountingboth the motor and transmission in such a manner that the templatefollowers .can move freely, and readily follow any change of directionwithout side thrust which would be the case if the mechanism was mountedon an immovable base or rigidly mounted with respect to the carriage.If, for instance, the motor Was not mounted on a plate movable withrespect. to the carriage the thrust or turning movement of the motorwould be directly transmitted to the carriage itself with the resultthat the template followers and there? fore the cutter or torch wouldhave a tendency to turn about a vertical axis instead of following thetemplate Without such skew- From the above it will be observed that ineach of the forms described there is a follower which is supported insubstantially a verth al position and guided along a predetermined path,viz the slide 27 in the first form, the pointer 52 in the second form,and

the sleeve 27 in the third form. Furthermore the follower in each formis propelled along a predetermined path .by a pair of driversdifferentially connected together and which are located u on oppositesides of the vertical axis of t e follower, viz in the loo for universalmovement in a plane, follower members supported from said means, meansfor rotating said follower members thereby to propel said support, and adifierential as sociated with said last means for maintaining the speedof said tool uniform.

3. In a machine of the class described, a

said elements on an axis normal to said plane, and means for maintainingthe average speed of said elements constant.-

5. In a machine of the class described, template follower elements,means for supporting said elements for, rotation on a vertical axis,means for holding the endso'f'said elements in engagement with atemplate, and means for positively rotating said elements at asubstantially constant average speed, thereby to propel said elementsand support in accordance with the contour of the template.

6. In a machine of the class template follower elements, means forsupporting said elements for rotation on a vertical axis, said elementsbeing arranged to engage opposite edges of a template, and means forpositively rotating said elements at substantially a constant averagespeed, thereby to propel said elements and support in accordance withthe contour of the template at a uniform rate of speed. s

7. In a machine of the class described, a template in the form of acontinuous strip, template followers engaging opposite sides of saidstrip, means for supporting said elements for rotation on a verticalaxis, and means for positively rotating said elements at a substantiallyconstant average speed thereby to propel said elements in accordancewith the contour of the template.

8. In a machine of the class described,.a template having an upstandingedge, template followers in rolling contact with the opposite sides ofsaid edge, means for supporting said followers for universal movement ina plane, and means for positively rotating said followers.

9. In a machine of the class described, a template having an upstandingedge, template followers in rolling contact with the opposite sides ofsaid edge,

. porting said followers for universal movement in a plane, and meansfor positively rotating said followers, including mechanism formaintaining the average speed thereof substantially constant.

10. In a machine of the class described, a thermal cutting tool, meansfor supporting said tool for universal movement in a plane, a templatehaving an edge to be followed, template followers in rolling contactwith the opposite sides of said edge respectively, and means forconjointly rotating said followers thereby to propel the support andelements in accordance with the contour of the template.

11. In a machine of the class described, a thermal cutting tool, meansfor supporting said tool for universal movement in a plane, a templatehaving an edge to be followed, template followers in rolling contactwith the opposite sides of said edge .respectively,

and means for conjointly rotating said foldescribed,

means for sup-.

' motor.

lowers thereby to propel the support and elements in accordance with thecontour of the template, said means including mechanism for maintainingthe average speed of? said elements substantially constant.

12. In a machine of the class described, a thermal cutting tool, meansfor supporting said tool for universal movement in a plane, a templatehaving an edge to be followed, template followers in rolling contactwith opposite sides of said edge, means for mounting said followers onsaid supporting means for rotation as a unit relative to said supportingmeans, and means for conjointly rotating said followers, said meansincluding a differential associated with said last means.

13. In a machine of the class described, a. template having an edge tobe followed, template followers in' rolling contact with opposite sidesof said edge, a support for said followers, a carriage, meansfor-rotatably mounting said support on the carriage, means for rotatingsaid followers, and a differential associated with said last. means formaintaining the average speed of said followers substantially constant.

14. A metal cutting machine comprising a carriage, an instrument mountedon the.

carriage, a motor associated with the car riage, two drive rollersconnected with the motor for propelling the carriage, and a differentialinterposed between the drive rollers and the motor.

15. A metal cutting machine comprising a carriage, an instrument mountedon the carriage for universal movement in a plane, a motor associatedwith the carriage, two drive rollers connected with the motor forpropelling the carriage, and a differential interposed between the driverollers and the motor.

16. A metal cutting machine comprising a carriage, an instrument mountedon the carriage for universal movement in a plane, a motor associatedwith the carriage, two drive rollers supported for rotation on avertical axis connected with the motor for propelling the carriage, anda'ditferential interposed between the drive rollers and the motor.

17. A metal cutting machine comprising a and carriage, an instrumentmounted on the carriage for universal movement in a plane, a motorassociated with the carriage, two drive rollers supported for rotationon a vertical axis and connected with the motor for propelling thecarriage, the rollers being arranged for. rolling contact with oppositeedges of a template, and a differential inter posed between the' driverollers and the 18. A metal cutting machine comprising a.

follower to be propelled along a predetermined path, a support for saidfollower, a

'pair of drivers to propel said follower, a motor for rotating saiddrivers, and a differential interposed between said drivers and motor.

19. A metal cutting machine comprising a vertically disposed follower tobe propelled along a predetermined path, a support for said follower, apair of drivers to propel.

said follower, a motor for rotating. said drivers. and a difierentialinterposed between said drivers and motor.

20. A metal cutting machine comprising a vertically disposed follower tobe propel ed along a-predetermined path, a support for said follower, aair of drivers on opposite sides of the vertlcal axis of the follower topropel said follower, a motor for rotating said drivers, and adifferential interposed between saiddrivers and motor.

21. A metal cutting machine comprising a follower supported foruniversal movement in a plane, a pair of drivers on opposite sides ofthe follower to propel said follower along a predetermined path, a motorfor rotating said drivers, and a differential interposed between saiddrivers and motor.

22. In a machine of the class described a cutting tool, means forsupporting said tool for universal movement in a plane, follower memberssupported from said means, means for positively rotating said followermembers to propel said support evenly, and means for maintaining theaverage speed of said members constant, said rotating means beingarranged to propel said support without tendency to deflect saidfollower members from their course.

23. A metal cutting machine comprising a carriage, an instrument mountedon the carriage for universalmovement in a plane, a support rotatablymounted with respect to said carriage, a motor carried by said support,two drive rollers supported for rotation on vertical axes and connectedwith the motor for propelling the carriage, and a differentialinterposed between the drive rollers and the motor.

24. A metalcutting machine comprising a carriage, an instrument mountedon the carriage for universal movement a plane, a support rotatablymounted with respect to said carriage, a motor carried by said support,two drive rollers supported for rotation on vertical axes and connectedwith the motor for propelling the carriage, said motor being mounted onsaid carriage for rotation about a vertical axis between said axeswhereby to avoid tendency for the motor to deflect the rollers fromtheir course, and a differential interposed between the drive rollersand the motor.

25. In a machine of the class described, a carriage mounted foruniversal movement in a plane, a cutting tool mounted onsaid carriageand movable therewith, follower elements mounted on said carriage, meansfor positively rotating said follower elements, said means being mountedon a support rotatable with respect to said carriage whereby the turningmoment of said rotating means causes no relative movement between thefollower elements and the support.

26. In a machine of the class described, a carriage mounted foruniversal movement in a plane, a cutting tool mounted on said .carriageand movable therewith, template follower elements mounted on saidcarriage, driving means for positively rotating said follower elementsmounted on said carriage, anti-frictional bearings between said drivingmeans and carriage whereby the thrust from the driving means will nottend to prevent the carriage and cutting tool from accurately followingthe course prescribed by the follower elements.

27 A metal cutting machine comprising a carriage, an instrument mountedon the carriage for universal movement in a plane, a support mounted onsaid carriage and rotata le in anti-frictional bearings with respectthereto, a motor. carried by said support, and template followers drivenby said motor to propel the carriage and impart a corresponding movementto the instrument mounted thereon.

Signed by us at Boston Mass. this fourth day of September 1924.

' ADOLF KREBS.

REXFORD B. GUPTILL.

